Material for 8.8 grade thread 1

[macPT]

I am designing a component that must end with a M8 mail thread. This thread will be manufactured by metal cutting and not cold formed. It should have the equivalent strength grade 8.8 (ISO 898-1). I am thinking in using CK45 (material DIN 1.1191), quenched (820ºC and oil)and tempered (550ºC). Does any one have better ideas?

Thanks

 

[CoryPad]

Refer to Table 2 in ISO 898-1 for material chemistry. You can select a lower carbon steel (~ 0.20-0.25 mass percent is commonly used) with a small boron addition that will provide improved toughness with no strength decrease.